System and method for increasing the depth of focus of the human eye

ABSTRACT

A method and apparatus for increasing the depth of focus of the human eye is comprised of a lens body, an optic in the lens body configured to produce light interference, and a pinhole-like optical aperture substantially in the center of the optic. The optic may be configured to produce light scattering or composed of a light reflective material. Alternatively, the optic may increase the depth of focus via a combination of light interference, light scattering, light reflection and/or light absorption. The optic may also be configured as a series of concentric circles, a weave, a pattern of particles, or a pattern of curvatures. One method involves screening a patient for an ophthalmic lens using a pinhole screening device in the lens to increase the patient&#39;s depth of focus. Another method comprises surgically implanting a mask in the patient&#39;s eye to increase the depth of focus.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a divisional of U.S. patentapplication Ser. No. 09/516,258, filed Feb. 29, 2000, which claimedpriority from provisional U.S. Patent Application Serial No. 60/122,001,filed Mar. 1, 1999, entitled “SCREENING TECHNIQUES AND DEVICES USEDPRIOR TO THE INSERTION OF A CORNEAL ANNULUS INLAY;” provisional U.S.Patent Application Serial No. 60/124,345, filed Mar. 15, 1999, entitled“NEW METHOD OF INCREASING THE DEPTH OF FOCUS OF THE HUMAN EYE;” andprovisional U.S. Patent Application Serial No. 60/138,110, filed Jun. 7,1999, entitled “WOVEN ANNULAR MASK CORNEAL INLAY.” The disclosures ofall these applications are incorporated herein, in their entirety, byreference.

TECHNICAL FIELD AND BACKGROUND ART

[0002] The invention generally relates to ophthalmic lenses and, moreparticularly, the invention relates to ophthalmic lenses for increasingthe depth of focus of the human eye.

[0003] It is well-known that the depth of focus of the human eye can beincreased with the use of ophthalmic lenses with pinhole-like aperturessubstantially near the optical center of the lens. For example, U.S.Pat. No. 4,976,732 (“the '732 patent”) discloses an ophthalmic lens witha pinhole-like aperture. In the '732 patent, a mask forms thepinhole-like aperture. In one embodiment, the mask is circular in shape.When the pupil is constricted, light enters the retina through thepinhole-like aperture. When the pupil is dilated, light enters theretina through the pinhole-like aperture and the outer edges of themask.

[0004] In addition, U.S. Pat. No. 3,794,414 (“the '414 patent”)discloses a contact lens with a pinhole-like aperture. In the '414patent, the mask forming the pinhole-like aperture has radial slitsand/or scalloped edges. In addition, the mask forming the pinhole-likeaperture is two spaced-apart concentric circles. However, the radialslits, scalloped edges and two spaced-apart concentric circles promotelight diffraction, which in turn reduces the contrast of the image.

[0005] In U.S. Pat. Nos. 4,955,904, 5,245,367, 5,757,458 and 5,786,883,various modifications to an ophthalmic lens with a pinhole-like apertureare disclosed. For example, the patents disclose use of an optical powerfor vision correction in the pinhole-like aperture, or use of an opticalpower for vision correction in the area outside the mask. In contrast,in U.S. Pat. No. 5,980,040, the mask is powered. In particular, the maskis powered to bend the light passing through the mask to impinge on theretina at a radial distance outside of the fovea. In other words, themask is powered to “defocus” the light.

[0006] In each of these patents, the mask forming the pinhole-likeaperture is made, in whole or in part, of a light absorptive material. Alight-absorptive material is a material in which light is lost as itpasses through the material, generally due to conversion of the lightinto another form of energy, e.g., heat.

SUMMARY OF THE INVENTION

[0007] In accordance with an embodiment of the invention, an ophthalmiclens comprises a lens body, an optic located in the lens body, the opticconfigured to produce light interference, and a pinhole-like opticalaperture substantially in the center of the optic. In a furtherembodiment of the invention, the optic is configured to positivelyinterfere with parallel light reaching the optic and negativelyinterfere with diverging light reaching the optic. In addition, somediverging light may pass through the optic. In this alternate embodimentof the invention, the optic is configured to spread out the diverginglight passing through the optic.

[0008] In an alternate embodiment of the invention, an ophthalmic lenscomprises a lens body, an optic located in the lens body, the opticconfigured to produce light scattering, and a pinhole-like opticalaperture substantially in the center of the optic. In a furtherembodiment of the invention, the optic is configured to forward scatterparallel light reaching the optic and back scatter diverging lightreaching the optic.

[0009] In another alternative embodiment of the invention, an ophthalmiclens comprises a lens body, an optic located in the lens body, the opticconfigured to produce light reflection, and a pinhole-like opticalaperture substantially in the center of the optic. In an alternateembodiment of the invention, the optic is composed, in whole or in part,of a light reflective material.

[0010] In further embodiments of the inventions, the optic may beconfigured as a series of concentric circles, a weave, a pattern ofparticles, or a pattern of curvatures. In addition, the pinhole-likeaperture includes an optical power for vision correction, and may have adiameter in the range of substantially 0.05 mm to substantially 5.0 mm.Further, the optic may have an outer diameter in the range ofsubstantially 1.0 mm to substantially 8.0 mm. The optic may also becomposed of a material having varying degrees of opacity, and theophthalmic lens and the optic may be composed of a bio-compatible,non-dissolving material, such as polymethyl methacrylate or a medicalpolymer.

[0011] In accordance with another embodiment of the invention, a methodfor screening a patient for an ophthalmic lens, the ophthalmic lenshaving a pinhole-like optical aperture, comprises fitting each of thepatient's eyes with a first contact lens, placing a mask on each of thefirst contact lens, the mask configured to produce a pinhole-likeaperture in each of the first contact lens, fitting each of thepatient's eyes with a second contact lens, the second contact lens beingplaced over the mask to hold the mask in a substantially constantposition, and testing the patient's vision.

[0012] In further embodiments of the invention, the mask may be a lightinterference mask, a light scattering mask, or a light reflective mask.The first contact lens may include an optical power for visioncorrection. In addition, each of the first and second contact lenses maybe soft contact lenses. Further, the mask for each of the patient's eyesmay have a light absorption of substantially 100%. In the alternative,the mask for each of the patient's eyes may be composed of a polarizedmaterial.

[0013] In still further embodiments of the invention, the process oftesting comprises testing the patient's acuity for distance vision underbright and dim lighting conditions, testing the patient's acuity fornear vision under bright and dim lighting conditions, and testing thepatient's contrast sensitivity under bright and dim lighting conditions.The process of testing may further comprise testing a patient's visualacuity using a night driving simulation. The night driving simulationmay include a series of objects and road signs under bright and dimlighting conditions, as well as having the patient face a simulatedoncoming automobile headlight.

[0014] In an alternate embodiment of the invention, the process oftesting comprises replacing the mask in one of the patient's eyes with amask having a light absorption of substantially 85% or less, then, ifneeded, replacing the mask in the patient's other eye with a mask havinga light absorption of substantially 85% or less. Further, the process oftesting comprises, if needed, removing the mask from one of thepatient's eyes.

[0015] In another alternate embodiment of the invention, the process oftesting comprises placing an analyzer in the spectacle plane of one ofthe patient's eyes, the analyzer including a polarizing element,rotating the polarizing element to achieve an optimal balance ofcontrast and brightness, and determining the resultant light absorptionof the mask. In addition, the process of testing may include evaluatingthe cosmetic appearance of the mask.

[0016] In accordance with a still another embodiment of the invention, amethod for implanting a mask in a cornea, the mask configured toincrease the depth of focus of the human eye, comprises removing theepithelial sheet, creating a depression in the Bowman's membrane, thedepression being of sufficient depth and width to expose the top layerof the stroma and accommodate the mask, placing the mask in thedepression, and placing the removed epithelial sheet over the mask. In afurther embodiment of the invention, the depression may extend into thetop layer of the stroma.

[0017] In an alternate embodiment of the invention, a method forimplanting a mask in a cornea, the mask configured to increase the depthof focus of the human eye, comprises hinging open a portion of theBowman's membrane, creating a depression in the top layer of the stroma,the depression being of sufficient depth and width to accommodate themask, placing the mask in the depression, and placing the hingedBowman's membrane over the mask.

[0018] In another alternate embodiment of the invention, a method forimplanting a mask in a cornea, the mask configured to increase the depthof focus of the human eye, comprises creating a channel in the top layerof the stroma, the channel being in a plane parallel to the cornea'ssurface, and placing the mask in the channel. In this embodiment, themask may be threaded into the channel, or the mask may be injected intothe channel.

[0019] In still another alternate embodiment of the invention, a methodfor implanting a mask in a cornea, the mask configured to increase thedepth of focus of the human eye, comprises penetrating the top layer ofthe stroma with an injecting device, and injecting the mask into the toplayer of the stroma with the injecting device. In this embodiment, theinjecting device may be a ring of needles. In addition, the mask may bea pigment, or the mask may be composed of pieces of pigmented materialsuspended in a bio-compatible medium. The pigmented material may be madeof a medical polymer, e.g., suture material.

[0020] In one other alternate embodiment of the invention, a method forimplanting a mask in a cornea, the mask configured to increase the depthof focus of the human eye, comprises hinging open a corneal flap, thecorneal flap comprising substantially the outermost 20% of the cornea,placing the mask on the cornea, and placing the hinged corneal flap overthe mask.

[0021] In still one other alternate embodiment of the invention, amethod for implanting a mask in a cornea, the mask configured toincrease the depth of focus of the human eye, comprises creating apocket in the stroma, the pocket being of sufficient size to accommodatethe mask, and-placing the mask in the created pocket.

[0022] In further embodiments of the inventions, the mask may be a lightinterference optic, a light scattering optic, or a light reflectiveoptic. In addition, the mask may block visual aberrations. In addition,after surgery, a contact lens may be placed over at least the affectedportion of the cornea.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The foregoing and other objects and advantages of the inventionwill be appreciated more fully from the following further descriptionthereof with reference to the accompanying drawings wherein:

[0024]FIGS. 1a and 1 b show an exemplary ophthalmic lens with anexemplary optic configured to produce light interference.

[0025]FIGS. 2a and 2 b show another exemplary ophthalmic lens withanother exemplary optic configured to produce light interference.

[0026]FIGS. 3a and 3 b show an exemplary ophthalmic lens with anexemplary optic configured to produce light scattering.

[0027]FIGS. 4a and 4 b show an exemplary ophthalmic lens with anexemplary optic configured to produce light reflection.

[0028]FIG. 5 shows an exemplary process for screening a patientinterested in an ophthalmic lens with a pinhole-like aperture using anexemplary pinhole screening device.

[0029]FIGS. 6a through 6 c show a mask, configured to increase the depthof focus of the human eye, inserted underneath the cornea's epitheliumsheet.

[0030]FIGS. 7a through 7 c show a mask, configured to increase the depthof focus of the human eye, inserted beneath the cornea's Bowman'smembrane.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0031] In accordance with an embodiment of the invention, an ophthalmiclens (e.g., a contact lens, an intra ocular lens, a corneal inlay lens,etc.) increases the depth of focus of the human eye through the use ofan optic. The optic surrounds a pinhole-like optical aperture near theoptical center of the lens. The pinhole-like aperture in conjunctionwith the optic increases the depth of focus of the human eye. Inparticular, the optic increases the depth of focus of the human eyeusing light interference, light scattering, light reflection, lightabsorption and/or a combination of one or more of these properties. Anoptic configured in accordance with the various embodiments of theinvention is referred to as a Paraxial Adaptive Optic™.

[0032]FIGS. 1a and 1 b show an exemplary ophthalmic lens with anexemplary optic configured to produce light interference. FIG. 1a showsa front view of the exemplary ophthalmic lens. FIG. 1b shows a side viewof the exemplary optic implanted in the cornea of a human eye.

[0033] Light interference is the additive process in which the amplitudeof two or more overlapping light waves is either attenuated orreinforced. For example, when two overlapping light waves are in-phase(the crest and trough of one wave coincides with the crest and trough ofthe other wave), then the amplitude of the resultant light wave isreinforced. This type of interference is referred to as positiveinterference. In contrast, when two overlapping light waves areout-of-phase (the crest of one wave coincides with the trough of theother wave), then the amplitude of the resultant light wave isattenuated. This type of interference is referred to as negativeinterference. Of course, light interference also occurs between the twoextremes of in-phase and out-of-phase.

[0034] As shown in FIG. 1a and 1 b, optic 100 is located substantiallyin the center of lens body 110. Optic 100 surrounds optical aperture 120located near the optical center of lens body 110. The specific locationof optical aperture 120 in lens body 110 varies in accordance with thepatient's eye. Specifically, optical aperture 120 is positioned in lensbody 10 to be concentric with the patient's pupil.

[0035] In operation, optical aperture 120 increases the depth of focusof the human eye via a “pinhole effect.” In particular, optical aperture120 increases depth of focus by limiting the light reaching the retinato plane wavefront light. In photonics, a wavefront is a surfaceconnecting all points equidistant from a source. Plane wavefront lightis relatively parallel light, e.g., light from a distant source. It is“relatively” parallel light because, in reality, even light from adistant star is diverging light. In contrast, convex wavefront light isrelatively diverging light, e.g., light from a near source. It is easierfor the human eye to focus plane wavefront light because the crystallinelens of the human eye can focus parallel light on the retina with littleor no accommodation. In accommodation, the crystalline lens, through theaction of the ciliary muscles, thickens and, thereby, changes its degreeof curvature.

[0036] In order to achieve a useful “pinhole effect,” optical aperture120 should have a diameter in the range of substantially 0.05millimeters (“mm”) to substantially 5.0 mm. In addition, in order to aidexamination of the retina and increase brightness when the pupil isdilated, the outer diameter of optic 100 should be in the range ofsubstantially 1.0 mm to substantially 8.0 mm. Moreover, to furtherimprove vision, optical aperture 120 may include an optical power forvision correction, e.g., correction for near vision, correction fordistance vision, correction for intermediate vision, etc. Also, the areaoutside optic 100 may include an optical power for vision correction.

[0037] In operation, optic 100 increases the depth of focus of the humaneye via its configuration. In particular, optic 100 is configured toproduce light interference via a series of concentric circles.Specifically, optic 100 is configured to reinforce relatively parallellight and attenuate relatively diverging light. When optic 100attenuates less than all of the relatively diverging light, then optic100 is further configured to spread out the diverging light that passesthrough optic 100, i.e., weakening the diverging light passing throughoptic 100. Thus, because diverging light is attenuated and/or weakened,the “pinhole effect” of optical aperture 120 is increased for relativelynear objects, producing a higher contrast depth of focus image ofrelatively near objects. Moreover, because parallel light is reinforced,the “pinhole effect” of optical aperture 120 is reduced, producing abrighter image of relatively distant objects.

[0038] Optic 100 is also configured to effect the chromatic aberrationof the human eye. The human eye's chromatic aberration, in which thesize of an image appears to change when the color of the image ischanged, results from the normal increase in refractive index toward theblue end of the color spectrum. In optic 100, the increase in refractiveindex is toward the red end of the color spectrum. Thus, optic 100 mayreduce or cancel the chromatic aberration of the human eye.

[0039] Further, optic 100 is configured to meet the specific needs ofthe patient. For example, a person of skill in the art understands that,among other things, the addition of concentric circles, the removal ofconcentric circles, the change in spacing between concentric circles,the varying of spacing between concentric circles, and the shape of theconcentric circles (e.g., oval, round, elliptical, etc.) would influencethe light interference properties of optic 100.

[0040]FIGS. 2a and 2 b show another exemplary ophthalmic lens withanother exemplary optic configured to produce light interference. Inthis exemplary embodiment, optic 200 is configured to produce lightinterference via a weave. As discussed in regard to optic 100, the weavereinforces relatively parallel light and attenuates relatively diverginglight. Depending on the weave's material, the weave may also absorblight coming into contact with the weave's material. FIG. 2a shows afront view of the exemplary ophthalmic lens. FIG. 2b shows a side viewof the exemplary optic implanted in the cornea of a human eye.

[0041] As discussed in regard to optic 100, optic 200 is configured tomeet the specific needs of the patient. For example, a person of skillin the art understands that, among other things, the density of theweave would influence the light interference properties of optic 200.

[0042]FIGS. 3a and 3 b show an exemplary ophthalmic lens with anexemplary optic configured to produce light scattering. FIG. 3a shows afront view of the exemplary ophthalmic lens. FIG. 3b shows a side viewof the exemplary optic implanted in the cornea of a human eye.

[0043] In general, light scattering is the deflection of light uponinteraction with a medium. Light is forward scattered when, uponinteraction with a medium, it is deflected through angles of 90° or lesswith respect to the original direction of motion. Light is backscattered when, upon interaction with a medium, it is deflected throughangles in excess of 90° with respect to the original direction ofmotion.

[0044] As shown in FIGS. 3a and 3 b, optic 300 is located substantiallyin the center of lens body 310. Optic 300 surrounds optical aperture 320located near the optical center of lens body 310. The specific locationof optical aperture 320 in lens body 310 varies in accordance with thepatient's eye. Specifically, optical aperture 320 is positioned in lensbody 310 to be concentric with the patient's pupil.

[0045] As discussed in regard to optical apertures 120 and 220, opticalaperture 320 increases the depth of focus of the human eye via a“pinhole effect.” Similarly, as discussed in regard to optics 100 and200, optic 300 increases the depth of focus of the human eye via itsconfiguration. In particular, optic 300 is configured to produce lightscattering via a pattern of particles. Specifically, optic 300 isconfigured to forward scatter relatively parallel light and back scatterrelatively diverging light. Thus, because diverging light is backscattered, the “pinhole effect” of optical aperture 320 is increased forrelatively near objects, producing a higher contrast depth of focusimage of relatively near objects. Moreover, because parallel light isforward scattered, the “pinhole effect” of optical aperture 320 isreduced, producing a brighter image of relatively distant objects.

[0046] Further, optic 300 is configured to meet the specific needs ofthe patient. For example, a person of skill in the art understands that,among other things, the light absorption of the particles, the index ofrefraction of the particles, the index of refraction of the mediasurrounding the particles, the size of the particles, and the spacebetween the particles would influence the light scattering properties ofoptic 300. In addition, optic 300 may be configured to produce lightinterference, as discussed in regard to optics 100 and 200.

[0047]FIGS. 4a and 4 b show an exemplary ophthalmic lens with anexemplary optic configured to produce light reflection. FIG. 4a shows afront view of the exemplary ophthalmic lens. FIG. 4b shows a side viewof the exemplary optic implanted in the cornea of a human eye.

[0048] Optic 400 is located substantially in the center of lens body410. Optic 400 surrounds optical aperture 420 located near the opticalcenter of lens body 410. The specific location of optical aperture 420in lens body 410 varies in accordance with the patient's eye.Specifically, optical aperture 420 is positioned in lens body 410 to beconcentric with the patient's pupil.

[0049] As discussed in regard to optical apertures 120, 220 and 320,optical aperture 420 increases the depth of focus of the human eye via a“pinhole effect.” Similarly, as discussed in regard to optics 100, 200and 300, optic 400 increases the depth of focus of the human eye via itsconfiguration. In particular, optic 400 is configured to reflect light,in whole or in part, via a pattern of curvatures. Specifically, optic400 is configured to favor transmission of the light to which theretinal rods are more sensitive, i.e., dim light and/or blue light, andto block the light to which retinal cones are more sensitive, i.e.,bright light. Thus, because bright light is blocked, the “pinholeeffect” of optical aperture 420 is increased for relatively nearobjects, producing a higher contrast depth of focus image of relativelynear objects. Moreover, because dim light and/or blue light istransmitted, the “pinhole effect” of optical aperture 420 is reduced,producing a brighter image of relatively distant objects.

[0050] In an alternate embodiment, optic 400 may be composed, in wholeor in part, of a light reflective material. A light reflective materialis a material that, in whole or in part, reflects back light coming intocontact with the material.

[0051] Further, optic 400 may be configured to meet the specific needsof the patient. For example, a person of skill in the art understandsthat, among other things, the type of material, the thickness ofmaterial, and the curvature of material would influence the lightreflective properties of optic 400. In addition, optic 400 may beconfigured to produce light interference and/or light scattering, asdiscussed in regard to optics 100, 200 and 300, respectively.

[0052] In a particular embodiment of the ophthalmic lens described inFIG. 4, optic 400 is composed of a light reflective material with a peaktransmission of substantially 550 nanometers (“nm”). A light-adaptedretina has a peak transmission at 550 nm. In contrast, a dark-adaptedretina has a peak transmission at 500 nm. Thus, an optic with a peaktransmission of substantially 550 nm filters out more light with a peaktransmission of 500 nm, i.e., bright light, than light with a peaktransmission of 550 nm, i.e., dim light. Thus, as discussed above,because bright light is blocked, the “pinhole effect” of opticalaperture 420 is increased for relatively near objects, producing ahigher contrast depth of focus image of relatively near objects.Moreover, because dim light is transmitted, the “pinhole effect” ofoptical aperture 420 is reduced, producing a brighter image ofrelatively distant objects.

[0053] Further, this particular embodiment of optic 400 may beconfigured to meet the specific needs of the patient. For example, aperson of skill in the art understands that, among other things, thepeak transmission of the mask may be changed, e.g., to a peaktransmission of 500 nm. In addition, the mask may be composed ofmaterial, other than light reflective material, which also allows thedesired peak transmissions.

[0054] In alternate embodiments, the optic is composed ofbio-compatible, non-dissolving material, e.g., polymethyl methacrylateor medical polymers. In addition, the optic may be composed, in whole orin part, of a light reflective material or, in whole or in part, of alight absorptive material. Further, the optic may be composed, in wholeor in part, of a material having varying degrees of opacity. The opticmay also be configured to produce light interference, light-scatteringand light reflection, or some combination of one or more of theseproperties. Moreover, the optic may be colored to match the color of apatient's iris.

[0055] In accordance with a further embodiment of the invention, apatient interested in an ophthalmic lens with a pinhole-like aperture isscreened using soft contact lenses and a mask, referred to as a pinholescreening device. The mask may be an optic as described in the priorart, an optic as described herein, or an optic combining one or more ofthese properties. After insertion of the pinhole screening device, thepatient's vision is tested.

[0056]FIG. 5 shows an exemplary process for screening a patientinterested in an ophthalmic lens with a pinhole-like aperture using anexemplary pinhole screening device. The process begins at step 500, inwhich the patient is fitted with soft contact lenses, i.e., a softcontact lens in placed in each of the patient's eyes. If needed, thesoft contact lenses may include vision correction. Next, at step 510, amask is placed on the soft contact lenses. The mask should be placedconcentric with the patient's pupil. In addition, the curvature of themask should parallel the curvature of the patient's cornea. The processcontinues at step 520, in which the patient is fitted with a second setof soft contact lenses, i.e., a second soft contact lens is placed overthe mask in each of the patient's eyes. The second contact lens holdsthe mask in a substantially constant position. Last, at step 530, thepatient's vision is tested. During testing, it is advisable to check thepositioning of the mask to ensure it remains concentric with thepatient's pupil.

[0057] A test of the patient's vision may include testing the patient'sacuity for distance vision under bright and dim lighting conditions,testing the patient's acuity for near vision under bright and dimlighting conditions, and testing the patient's contrast sensitivityunder bright and dim lighting conditions. In addition, the test mayinclude testing the patient's visual acuity using a night drivingsimulation. A night driving simulation may include a series of objectsand road signs under bright and dim lighting conditions, as well as asimulated oncoming automobile headlight.

[0058] The test of the patient's vision may further include changing themask. For example, the test might first be conducted using, in each ofthe patient's eyes, a mask having a light absorption of substantially100%. If, for example, the patient experiences a sense of dimness, themask in one of the patient's eyes may be replaced with a mask having alight absorption of substantially 85%. If, for example, the sense ofdimness continues, the mask in the patient's other eye may be replacedwith a mask having a light absorption of substantially 85%. Then, forexample, if the sense of dimness continues, the mask may be removed fromone of the patient's eyes.

[0059] In the alternate, the mask in one of the patient's eyes may bereplaced with a mask having a light absorption less than substantially85%. If, for example, the patient experiences a sense of dimness with amask having a light absorption of substantially 100%, then the mask inone of the patient's eyes may be replaced with a mask having a lightabsorption of substantially 75%. If, for example, the sense of dimnesscontinues, the mask in the patient's other eye may be replaced with amask having a light absorption of substantially 75%. Then, for example,if the sense of dimness continues, the 75% mask may be replaced with amask having a light absorption of substantially 50%.

[0060] As can be seen, there are numerous permutations for thoroughlyscreening the patient to find the optimal balance of contrast andbrightness. In effect, the, mask in each of the patient's eyes isreplaced, every other time, with a mask having a different lightabsorption than the replaced mask. This process continues until theoptimal balance of contrast and brightness is found.

[0061] The process for changing the mask while testing the patient'svision also includes changing from an optic as described in the priorart to an optic as described herein. In addition, various maskconfigurations may be used. For example, an optic having both lightinterference and light scattering may be used, or an optic having bothlight reflective and light absorptive properties may be used. Onceagain, the numerous permutations allow for thoroughly screening thepatient to find the optimal balance of contrast and brightness prior to,for example, the doctor placing a customized order or the patientundergoing invasive surgery.

[0062] The test of the patient's vision may also include evaluating thecosmetic appearance of the mask. For example, if the patient isdissatisfied with the appearance of the mask, the mask can be replacedwith a mask of appropriate configuration colored to match the patient'siris.

[0063] In an alternate testing process, the mask placed on the softcontact lens in each of the patient's eyes is composed of a polarizedmaterial. A polarized material has a light absorption of substantially50%. Then, an analyzer, which contains a polarized element, is used tohelp calculate the patient's optimal light absorption properties for themask. In the process, the analyzer is placed in the spectacle plane ofone of the patient's eyes and the polarized element in the analyzer isrotated until the patient experiences an optimal balance of contrast andbrightness. The process may be repeated for the patient's other eye.

[0064] Using the analyzer, the doctor may now calculate the resultantlight absorption of the mask. If desired, a mask of similar lightabsorption, whether it be an optic as described in the prior art, anoptic as described herein, or an optic combining one or more of theseproperties, can now be placed between the contact lenses in each of thepatient's eyes and the patient's vision tested, as described above.

[0065] In accordance with a still further embodiment of the invention, amask is surgically implanted into the eye of a patient interested inincreasing his or her depth of focus. For example, the patient maysuffer from presbyopia, a condition in which the crystalline lens can nolonger accommodate near vision because of a loss of elasticity in thelens or a weakness in the ciliary muscle. The mask may be an optic asdescribed in the prior art, an optic as described herein, or an opticcombining one or more of these properties. Further, the mask may beconfigured to correct visual aberrations. To aid the surgeon surgicallyimplanting a mask into a patient's eye, the mask may be pre-rolled orfolded for ease of implantation.

[0066] The mask may be implanted in several locations. For example, themask may be implanted underneath the cornea's epithelium sheet, beneaththe cornea's Bowman membrane, in the top layer of the cornea's stroma,or in the cornea's stroma. When the mask is placed underneath thecornea's epithelium sheet, removal of the mask requires little more thanremoval of the cornea's epithelium sheet.

[0067]FIGS. 6a through 6 c show mask 600 inserted underneath epitheliumsheet 610. In this embodiment, the surgeon first removes epitheliumsheet 610. For example, as shown in FIG. 6a, epithelium sheet 610 may berolled back. Then, as shown in FIG. 6b, the surgeon creates depression615 in Bowman's member 620. Depression 615 should be of sufficient depthand width to both expose top layer 630 of stroma 640 and to accommodatemask 600. Mask 600 is then placed in depression 615. Last, epitheliumsheet 610 is placed over mask 600. Over time, as shown in FIG. 6c,epithelium sheet 610 will grow and adhere to top layer 630 of stroma640, as well as mask 600 depending, of course, on the composition ofmask 600. As needed, a contact lens may be placed over the incisedcornea to protect the mask.

[0068]FIGS. 7a through 7 c show mask 700 inserted beneath Bowman'smembrane 720. In this embodiment, as shown in FIG. 7a, the surgeon firsthinges open Bowman's member 720. Then, as shown in FIG. 7b, the surgeoncreates depression 715 in top layer 730 of stroma 740. Depression 715should be of sufficient depth and width to accommodate mask 700. Then,mask 700 is placed in depression 715. Last, Bowman's member 720 isplaced over mask 700. Over time, as shown in FIG. 7c, epithelium sheet710 will grow over the incised area of Bowman's member 720. As needed, acontact lens may be placed over the incised cornea to protect the mask.

[0069] In an alternate embodiment, a mask of sufficient thinness, i.e.,less than substantially 20 microns, may be placed underneath epitheliumsheet 610, or beneath Bowman's member 720, without creating a depressionin the top layer of the stroma.

[0070] In an alternate method for surgically implanting a mask in theeye of a patient, the mask may be threaded into a channel created in thetop layer of the stroma. In this method, a curved channeling toolcreates a channel in the top layer of the stroma, the channel being in aplane parallel to the surface of the cornea. The channeling tool eitherpierces the surface of the cornea or, in the alternative, is insertedvia a small superficial radial incision. In the alternative, a laserfocusing an ablative beam may create the channel in the top layer of thestroma. In this embodiment, the mask may be a single segment with abreak, or it may be two or more segments.

[0071] In another alternate method for surgically implanting a mask inthe eye of a patient, the mask may be injected into the top layer of thestroma. In this embodiment, an injection tool with a stop penetrates thesurface of the cornea to the specified depth. For example, the injectiontool may be a ring of needles capable of producing a mask with a singleinjection. In the alternative, a channel may first be created in the toplayer of the stroma. Then, the injector tool may inject the mask intothe tunnel. In this embodiment, the mask may be a pigment, or it may bepieces of pigmented material suspended in a bio-compatible medium. Thepigment material may be made of a polymer or, in the alternative, madeof a suture material.

[0072] In still another alternate method for surgically implanting amask in the eye of a patient, the mask may be placed beneath the cornealflap created during keratectomy, when the outermost 20% of the cornea ishinged open.

[0073] In one still other alternate method for surgically implanting amask in the eye of a patient, the mask may be placed in a pocket createdin the cornea's stroma.

[0074] Although various exemplary embodiments of the invention have beendisclosed, it should be apparent to those skilled in the art thatvarious changes and modifications can be made which will achieve some ofthe advantages of the invention without departing from the true scope ofthe invention. These and other obvious modifications are intended to becovered by the appended claims.

What is claimed is:
 1. An ophthalmic lens comprising: a lens body; anoptic located in the lens body, the optic configured to produce lightinterference; and a pinhole-like optical aperture substantially in thecenter of the optic.
 2. The ophthalmic lens according to claim 1 whereinthe optic is configured as a pattern of particles.
 3. The ophthalmiclens according to claim 1 wherein the pinhole-like aperture includes anoptical power for vision correction.
 4. The ophthalmic lens according toclaim 1 wherein the pinhole-like aperture has a diameter in the range ofsubstantially 0.05 mm to substantially 5.0 mm.
 5. The ophthalmic lensaccording to claim 1 wherein the optic has an outer diameter in therange of substantially 1.0 mm to substantially 8.0 mm.
 6. The ophthalmiclens according to claim 1 wherein the optic is composed of a materialhaving varying degrees of opacity.
 7. The ophthalmic lens according toclaim 1 wherein the ophthalmic lens is composed of a bio-compatible,non-dissolving material.
 8. The ophthalmic lens according to claim 1wherein the optic is composed of a bio-compatible, non-dissolvingmaterial.
 9. The ophthalmic lens according to claim 7 or claim 8 whereinthe bio-compatible, non-dissolving material is polymethyl methacrylate.10. The ophthalmic lens according to claim 7 or claim 8 wherein thebio-compatible, non-dissolving material is a medical polymer.
 11. Anophthalmic lens comprising: a lens body; an optic located in the lensbody, the optic configured to produce light scattering; and apinhole-like optical aperture substantially in the center of the optic.12. The ophthalmic lens according to claim 11 wherein the optic isconfigured to forward scatter parallel light reaching the optic and backscatter diverging light reaching the optic.
 13. The ophthalmic lensaccording to claim 11 wherein the optic is configured as a pattern ofparticles.
 14. The ophthalmic lens according to claim 11 wherein thepinhole-like aperture includes an optical power for vision correction.15. The ophthalmic lens according to claim 11 wherein the pinhole-likeaperture has a diameter in the range of substantially 0.05 mm tosubstantially 5.0 mm.
 16. The ophthalmic lens according to claim 11wherein the optic has an outer diameter in the range of substantially1.0 mm to substantially 8.0 mm.
 17. The ophthalmic lens according toclaim 11 wherein the optic is composed of a material having varyingdegrees of opacity.
 18. The ophthalmic lens according to claim 11wherein the ophthalmic lens is composed of a bio-compatible,non-dissolving material.
 19. The ophthalmic lens according to claim 11wherein the optic is composed of a bio-compatible, non-dissolvingmaterial.
 20. The ophthalmic lens according to claim 18 or claim 19wherein the bio-compatible, non-dissolving material is polymethylmethacrylate.
 21. The ophthalmic lens according to claim 18 or claim 19wherein the bio-compatible, non-dissolving material is a medicalpolymer.
 22. An ophthalmic lens comprising: a lens body; an opticlocated in the lens body, the optic configured to produce lightreflection; and a pinhole-like optical aperture substantially in thecenter of the optic.
 23. The ophthalmic lens according to claim 22wherein the optic is composed of a light reflective material.
 24. Theophthalmic lens according to claim 22 wherein the optic is partiallycomposed of a light reflective material.
 25. The ophthalmic lensaccording to claim 22 wherein the optic is composed of a pattern ofcurvatures.
 26. The ophthalmic lens according to claim 22 wherein theoptic is configured as a series of concentric circles.
 27. Theophthalmic lens according to claim 22 wherein the optic is configured asa weave.
 28. The ophthalmic lens according to claim 22 wherein the opticis configured as a pattern of particles.
 29. The ophthalmic lensaccording to claim 22 wherein the pinhole-like aperture includes anoptical power for vision correction.
 30. The ophthalmic lens accordingto claim 22 wherein the pinhole-like aperture has a diameter in therange of substantially 0.05 mm to substantially 5.0 mm.
 31. Theophthalmic lens according to claim 22 wherein the optic has an outerdiameter in the range of substantially 1.0 mm to substantially 8.0 mm.32. A method for increasing the depth of focus of the human eye, themethod comprising: providing an ophthalmic lens, the ophthalmic lenscomprising a lens body, an optic, located in the lens body, the opticconfigured to produce light interference, and a pinhole-like opticalaperture substantially in the center of the optic; and fitting theophthalmic lens.
 33. A method for increasing the depth of focus of thehuman eye, the method comprising: providing an ophthalmic lens, theophthalmic lens comprising a lens body, an optic located in the lensbody, the optic configured to produce light scattering, and apinhole-like optical aperture substantially in the center of the optic;and fitting the ophthalmic lens.
 34. The method according to claim 33wherein the optic is configured to forward scatter parallel lightreaching the optic and to back scatter diverging light reaching theoptic.
 35. A method for increasing the depth of focus of the human eye,the method comprising: providing an ophthalmic lens, the ophthalmic lenscomprising a lens body, an optic located in the lens body, the opticconfigured to produce light reflection, and a pinhole-like opticalaperture substantially in the center of the optic; and fitting theophthalmic lens.
 36. The ophthalmic lens according to claim 35 whereinthe optic is composed of a light reflective material.
 37. The methodaccording to claim 35 wherein the optic is partially composed of a lightreflective material.
 38. A method for screening a patient for anophthalmic lens, the ophthalmic lens having a pinhole-like opticalaperture, the method comprising: fitting each of the patient's eyes witha first contact lens; placing a mask on each of the first contact lens,the mask configured to produce a pinhole-like aperture in each of thefirst contact lens; fitting each of the patient's eyes with a secondcontact lens, the second contact lens being placed over the mask to holdthe mask in a substantially constant position; and testing the patient'svision.
 39. The method of claim 38 wherein the mask is a lightinterference optic.
 40. The method of claim 38 wherein the mask is alight scattering optic.
 41. The method of claim 38 wherein the mask is alight reflective optic.
 42. The method of claim 38 wherein each of-thefirst contact lenses includes an optical power for vision correction.43. The method of claim 38 wherein each of the first and second contactlenses are soft contact lenses.
 44. The method of claim 38 wherein themask for each of the patient's eyes has a light absorption ofsubstantially 100%.
 45. The method of claim 38 wherein the mask for eachof the patient's eyes is composed of a polarized material.
 46. Themethod of claim 38 wherein the process of testing further comprises:testing the patient's acuity for distance vision under bright lightingconditions; testing the patient's acuity for near vision under brightlighting conditions; and testing the patient's contrast sensitivityunder bright lighting conditions.
 47. The method of claim 38 wherein theprocess of testing further comprises: testing the patient's acuity fordistance vision under dim lighting conditions; testing the patient'sacuity for near vision under dim lighting conditions; and testing thepatient's contrast sensitivity under dim lighting conditions.
 48. Themethod of claim 38 wherein the process of testing further comprises:testing a patient's visual acuity using a night driving simulation. 49.The method of claim 48 wherein the night driving simulation includes aseries of objects and road signs under bright lighting conditions. 50.The method of claim 48 wherein the night driving simulation includes aseries of objects and road signs under dim lighting conditions.
 51. Themethod of claim 48 wherein the night driving simulation includes thepatient facing a simulated oncoming automobile headlight.
 52. The methodof claim 44 wherein the process of testing further comprises: replacingthe mask in one of the patient's eyes with a mask having a lightabsorption of substantially 85%.
 53. The method of claim 52 wherein theprocess of testing further comprises: replacing the mask in thepatient's other eye with a mask having a light absorption ofsubstantially 85%.
 54. The method of claim 53 wherein the process oftesting further comprises: removing the mask from one of the patient'seyes.
 55. The method of claim 44 wherein the process of testing furthercomprises: replacing the mask in one of the patient's eyes with a maskhaving a light absorption less than substantially 85%.
 56. The method ofclaim 55 wherein the process of testing further comprises: replacing themask in the patient's other eye with a mask having a light absorptionless than substantially 85%.
 57. The method of claim 56 wherein theprocess of testing further comprises: removing the mask from one of thepatient's eyes.
 58. The method of claim 45 wherein the process oftesting further comprises: placing an analyzer in the spectacle plane ofone of the patient's eyes, the analyzer including a polarizing element;rotating the polarizing element to achieve an optimal balance ofcontrast and brightness; and determining the resultant light absorptionof the mask.
 59. The method of claim 38 wherein the process of testingfurther comprises evaluating the cosmetic appearance of the mask.
 60. Amethod for implanting a mask in a cornea, the mask configured toincrease the depth of focus of the human eye, the cornea comprising anepithelial sheet, a Bowman's member, and a stroma, the stroma having atop layer, the method comprising: removing the epithelial sheet;creating a depression in the Bowman's membrane, the depression being ofsufficient depth and width to expose the top layer of the stroma andaccommodate the mask; placing the mask in the depression; and placingthe removed epithelial sheet over the mask.
 61. The method according toclaim 60 wherein the mask is a light interference optic.
 62. The methodaccording to claim 60 wherein the mask is a light scattering optic. 63.The method according to claim 60 wherein the mask is a light reflectiveoptic.
 64. The method according to claim 60 wherein the mask blocksvisual aberrations.
 65. The method according to claim 60, furthercomprising: placing a contact lens over at least the affected portion ofthe cornea until the epithelial sheet has adhered to the mask and thetop layer of the stroma.
 66. The method according to claim 60 whereinthe depression extends into the top layer of the stroma.
 67. A methodfor implanting a mask in a cornea, the mask configured to increase thedepth of focus of the human eye, the cornea comprising an epithelialsheet, a Bowman's member, and a stroma, the stroma having a top layer,the method comprising: hinging open a portion of the Bowman's membrane;creating a depression in the top layer of the stroma, the depressionbeing of sufficient depth and width to accommodate the mask; placing themask in the depression; and placing the hinged Bowman's membrane overthe mask.
 68. The method according to claim 67 wherein the mask is alight interference optic.
 69. The method according to claim 67 whereinthe mask is a light scattering optic.
 70. The method according to claim67 wherein the mask is a light reflective optic.
 71. The methodaccording to claim 67 wherein the mask blocks visual aberrations. 72.The method according to claim 67, further comprising: placing a contactlens over at least the affected portion of the cornea until theepithelial sheet has grown over the hinged Bowman's membrane.
 73. Amethod for implanting a mask in a cornea, the mask configured toincrease the depth of focus of the human eye, the cornea comprising anepithelial sheet, a Bowman's member, and a stroma, the stroma having atop layer, the method comprising: creating a channel in the top layer ofthe stroma, the channel being in a plane parallel to the cornea'ssurface; and placing the mask in the channel.
 74. The method accordingto claim 73 wherein the mask is a light interference optic.
 75. Themethod according to claim 73 wherein the mask is a light scatteringoptic.
 76. The method according to claim 73 wherein the mask is a lightreflective optic.
 77. The method according to claim 73 wherein the maskblocks visual aberrations.
 78. The method according to claim 73 whereinthe mask is threaded into the channel.
 79. The method according to claim73 wherein the mask is injected into the channel.
 80. A method forimplanting a mask in a cornea, the mask configured to increase the depthof focus of the human eye, the cornea comprising an epithelial sheet, aBowman's member, and a stroma, the stroma having a top layer, the methodcomprising: penetrating the top layer of the stroma with an injectingdevice; and injecting the mask into the top layer of the stroma with theinjecting device.
 81. The method according to claim 80 wherein the maskis a light interference optic.
 82. The method according to claim 80wherein the mask is a light scattering optic.
 83. The method accordingto claim 80 wherein the mask is a light reflective optic.
 84. The methodaccording to claim 80 wherein the mask blocks visual aberrations. 85.The method according to claim 80 herein the injecting device is a ringof needles.
 86. The method according to claim 79 or claim 80 wherein themask is a pigment.
 87. The method according to claim 79 or claim 80wherein the mask is composed of pieces of pigmented material suspendedin a bio-compatible medium.
 88. The method according to claim 87 whereinthe pigmented material is a medical polymer.
 89. The method according toclaim 87 wherein the medical polymer is suture material.
 90. A methodfor implanting a mask in a cornea, the mask configured to increase thedepth of focus of the human eye, the cornea comprising an epitheliumsheet, the method comprising: hinging open a corneal flap, the cornealflap comprising substantially the outermost 20% of the cornea; placingthe mask on the cornea; and placing the hinged corneal flap over themask.
 91. The method according to claim 90 wherein the mask is a lightinterference optic.
 92. The method according to claim 90 wherein themask is a light scattering optic.
 93. The method according to claim 90wherein the mask is a light reflective optic.
 94. The method accordingto claim 90 wherein the mask blocks visual aberrations.
 95. The methodaccording to claim 90, further comprising: placing a contact lens overat least the affected portion of the cornea until the epithelial sheethas grown over the hinged corneal flap.
 96. A method for implanting amask in a cornea, the mask configured to increase the depth of focus ofthe human eye, the cornea comprising a stroma, the method comprising:creating a pocket in the stroma, the pocket being of sufficient size toaccommodate the mask; and placing the mask in the created pocket. 97.The method according to claim 96 wherein the mask is a lightinterference optic.
 98. The method according to claim 96 wherein themask is a light scattering optic.
 99. The method according to claim 96wherein the mask is a light reflective optic.
 100. The method accordingto claim 96 wherein the mask blocks visual aberrations.
 101. Anophthalmic lens comprising: a lens body; an optic located in the lensbody, the optic configured to produce L, wherein L is lightinterference, light scattering, or light reflection; and a pinhole-likeoptical aperture substantially in the center of the optic.
 102. Theophthalmic lens according to claim 101 wherein the optic is composed ofa material having varying degrees of opacity.
 103. The ophthalmic lensaccording to claim 101 wherein the ophthalmic lens is composed of abio-compatible, non-dissolving material.
 104. The ophthalmic lensaccording to claim 101 wherein the optic is composed of abio-compatible, non-dissolving material.
 105. The ophthalmic lensaccording to claim 103 or claim 104 wherein the bio-compatible,non-dissolving material is polymethyl methacrylate.
 106. The ophthalmiclens according to claim 103 or claim 104 wherein the bio-compatible,non-dissolving material is a medical polymer.
 107. The ophthalmic lensaccording to claim 101 wherein the pinhole-like aperture includes anoptical power for vision correction.